Polymeric titanium compounds



Patented Dec. 9, 1952 POLYMERIC TITANIUM COMPOUNDS Carl MartinLangkammerer, Wilmington, Del.,

assignor to pany, Wilmington, ware E. I. du Pont de Nemours and DeL, acorporation of Dela- Com- No Drawing. Application June 2'7, 1950, SerialNo. 170,703

20 Claims.

This invention relates to polymeric titanic acid esters andester-carboxylates, and to novel methods for effecting theirpreparation. More particularly, it relates to a method for preparingorgano-soluble polymeric titanium compounds of the type mentionedthrough the reaction of organic esters of ortho-titanic acid with asubstantially anhydrous aliphatic carboxylic acid.

This application is a continuation-in-part of my copending applicationSer. No. 751,139, filed May 28, 1947.

It is known that tetraalkyl ortho-titanates hydrolyze in the presence ofwater to form titania gel. It has been found that tetraalkyl titanates,on treatment with, for instance, acetic acid, form soluble polytitanatesand, as lay-products, esters and alcohols corresponding to the alkylgroups originally present in the alkyl titanates.

An object of this invention is to provide new polymeric titanium estersand novel methods of preparing such esters of polytitanic acid. Anotherobject is to provide a readily-controllable method for the preparationof new, high-molecular-weight polymeric esters and ester-carboxylates ofpolytitanic acid which possesses unique solubility characteristics inorgano, especially hydrocarbon, solvents, to provide solutions exhibitinnovel surface-active effects and adaptable for use in a wide variety ofcommercial applica tions. Further objects and advantages of theinvention will appear hereinafter.

In accordance with this invention, an orthotitanate of the formulaTi(OR) 4, where R, is alkyl, cycloalkyl, aryl, or aralkyl, is reacted inthe presence or absence of an organic solvent with at least one-halfmolar equivalent of a substantially anhydrous, aliphatic monocarboxylicacid, the reaction being allowed to continue until the desired solublepolymeric polytitanic acid ester or ester-carboxylate is formed.

In a more specific and preferred embodiment, the invention comprisesheating an alkyl orthotitanate, such as tetraethyl titanate, and from tol mols of a straight-chain,saturated ali phatic monocarboxylic acid permol of ortho-titanate, until a stable, soluble polymeric polytitanicester is formed.

In one practical adaptation of the invention, employing, for example,tetraethyl titanate, the ortho-titanate is mixed with an anhydrousaliphatic carboxylic acid, for example, glacial acetic acid, and in theproportions of from to 2 mols of acid per mol of ortho-titanate. Thereactants are then heated for a period of about one hour at temperaturesranging from 50 C.- 100 C. under a reflux condenser, the resultingby-product ethanol and ethyl acetate formed being then distilled off asa binary boiling at '71-'72 C. If mol of glacial acetic acid per mol oftetraethyl titanatc is used, the chief product is a dimer, hexaethyldititanate. acid per mol of titanate, an organic-solvent solublepolymeric titanium ester is formed. If 2 or more mols of glacial aceticacid per mol of titanate ester are used, a high-molecular-weightpolymeric titanium ester containing carboxylate groups is formed andsome degree of branching and ring closure may result. Thehydrocarbonsoluble polymeric titanium esters which remain in thedistillation apparatus can be removed and used as such, or they can befreed from impurities and by-products by resorting to conventionalfractional extraction, vacuum distillation, or other desired recovery orpurification methods.

The polymeric titanic acid ester products of this invention arecolorless to light-brown liquids and solids. They are unique in thatthey are readily soluble in organic solvents, such as chloroform,benzene, toluene, xylene, etc., the resulting solutions exhibiting noveland desired surface-active properties.

This invention is further illustrated by the following examples, inwhich parts are by Weight:

Example I Four hundred and forty-eight parts of tetraethyl titanate and2&0 parts of glacial acetic acid were heated under a distillation columnand allowed to reflux for one hour. The reaction mixture was thensubjected to distillation at atmospheric pressure and a total of 334parts of a binary of ethyl acetate and ethanol, boiling at 11-'72 C. wascollected. The pale yellow residue remaining in the distillation vesselwas soluble in benzene.

Erample II Two hundred twenty-eight parts of tetraethyl titanate andparts of glacial acetic acid were heated under a distillation column and124 parts of a binary of ethanol and ethyl acetate distilling at 71-72"C. was collected. The residue was then treated under a high vacuum toremove any remaining volatile materials. A solid product weighing 153parts was obtained. It was soluble in benzene and other organicsolvents. Upon analysis, it contained 30.4 percent of titanium. Thetheoretical value for [-TiO(OC2I-I5)2-]n is 31.2 percent titanium.

Example III Three hundred forty parts of tetrabutyl titanate and 60parts of glacial acetic acid were heated under a distillation column anda total of 192 parts of a mixture of butanol and butyl acetate wasdistilled ofi at a temperature of C.-12G C. Remaining volatile materialwas removed by treatment with a vacuum. The product was a light-brownviscous liquid.

With 1 mol of Example IV Four hundred twenty-six and seven-tenths ramsof stearic acid were dissolved in 900 cc. of toluene and 142.1 grams oftetraisopropyl titanatewere added. One hundred fifty-five cc. of anazeotrope of toluene and isopropyl alcohol (B. P. 79.6-81 C.)-wereseparated by fractional distillation, and the remainder of thetoluene was removed. in vacuo. A large portion (338.2 grams) of theproduct was melted and extracted withacetonitrile in a liquid-liquidextractorat about 72 C. In the first 19-hours, 149.6 grams of materialwhich was Ti-free. and which solidih lied on cooling was extracted. Inthe next 52 hours, 9.4 gramsof Ti-freesolid wereremoved, and in thefinal 72 hours, 2.0 grams of Ti-free solid were removed. Theorange-brown, lowmelting, wax-like product corresponded toasesquistearate in analysis:

CI)CJH7 ?OCC17H35 CaH7O-- Ti o 'r10- a O C 017E135 00.171135 3 I Calcd.Found Ti ..Pcrcent 9.07 9. 25, 9. 40 "do; 65. 90 66. 23, 66.15 do 10.9010.80, 10.77 d0 0.0 0.11, 0.06 M01. Wt 3, 171 2, 730, 2, 880

Ewample. VI

A solution of 68.1 grams (0.2'mol) of tetrabutyl titanate and 227.6grams (0.8 mol) of stearic acid in 65000. of toluene was refluxed, andtoluene/butyl alcohol azeotrope containing small droplets of water withwithdrawn at the top of a fractionating column. Removal of the remainderof the toluene left 261.7 grams of soft, light-brown solid which waspulverized and twice extracted with acetone, first with 1000 cc. andthen with 800. cc. moved 133'grams of Ii'--free. solid, and'the second19.1 grams of Ti-free solid. The resulting distearate melted at51.6-52.4 0. and corresponded in analysis to:

Example VII A- solution of 85.1. g. (0.25 mol) of tetrabutyl titanateand 142.3 g. (0.5.mol)' of stearic acid in 700 cc..of toluene was1'efluxed-,.and.butyl a-lco- The first extraction. re-

hol-toluene azeotrope (150 00., B. P. about C.) was separated byfractional distillation. Removal of the remainder of the toluene invacuo left a tan solid which weighed 231.6 g. and which had a T102content of 10.56%. Although the T102 content corresponded closely to thecalculated value (10.63% T102) for the product was actually found to bea mixture as was shown both by continuous extraction with hotacetonitrile and by batch extraction with acetone at room temperature:

(a) Extraction with acetonitrile removed 47.8% by weight of Ti-free oiland left a solid, polymeric monostearate'which had a T102 content of20.34%.

(b) Extraction with acetone removed 48.3% by weight of Ti-free oil andleft a monostearate with a T102 content of 21.15%.

The purified product melted at 69.6-7211 C. and corresponded closely inanalysis to the monostearate:

Although described as applied to certain specific embodiments, theinvention is not to be construed as limited thereto. Hence, variancetherefrom can be resorted to withoutdeparting'from its underlyingprinciples and scope.

The exact structure of the organic polymeric titanium compounds of thisinvention is not presently known to me, but their composition appears todepend on the ratio of acid to orthotitanic ester used, as indicated inthe following equations, wherein R is a hydrocarbon radical selectedfrom the group alkyl, cycloalkyl, aryl and aralkyl, and R is amonovalent aliphatic hydrocarbon radical containing from 1-20 carbonOOCR In lieu Of the tetra-ortho-titanatcs mentioned, other organictitanates corresponding to the gen eral formula- Ti(OR)4, and especiallythose in which R. is an alkyl hydrocarbon radical of an alcoholcontaining from 112 carbon atoms, can be used. Specific examples ofusefully-employable tetra-ortho-titanates include those of ethylortho-titanate, methyl ortho-titanate, isopropyl ortho-titanate, amylortho-titanate, octyl orthotitanate, dodecyl ortho-titanate, as well as2- ethylhexyl, benzyl, cyclohexyl, phenyl, ethoxyethyl, andbeta-naphthyl ortho-titanates, etc.

Although use is preferred of saturated, aliphatic monocarboxylic acids,other aliphatic carboxylic acids, including those containing up to andincluding carbon atoms, can also be employed.

Specific examples of such acids include those of acetic, propionic,butyric, valeric, caproic, heptylic, caprylic, nonylic, capric, lauric,myristic, palmitic, dodecanoic, oleic, ricinoleic, linoleic, stearic,beta-oleostearic, or arachidic, etc.

As already indicated, the molecular ratio of carboxylic acid totetraortho-titanate determines the nature of the ultimate product andthis ratio should be at least 0.5:1.0. For the preparation of the simplepolymeric titanium esters, the preferred ratio of acid to ortho-titanateis 1:1. If two or more mols of acid per mo1 of ortho-titanate are used,the resulting polymeric ester is a titanium ester carboxylate. Theexpression polymeric titanium ester, as herein employed, is generic tothe simple polymeric esters (resulting from the use of, say, a 1:1 ratioof acid to alkyl ortho-titanate) as well as to the polymeric titaniumester-carboxylate (resulting from the use of acid to alkylortho-titanate ratios of 2:1 and higher).

While, in obtaining optimum benefits under my invention, I prefer toemploy from to 4 mols of carboxylic acid per mol of tetraalkylortho-titanate, use can be made, if desired, of

amounts of acid up to, say, 5 or 6 mols or higher per mol of theortho-titanate. However, since no beneficial effects are realized .whenresort is had to such higher amounts, and in some instancesdisadvantageous results may be realized, particularly in respect toyield, the employment of higher amounts of acid than the indicatedpreferred range is not recommended.

The reaction between the ortho-titanates and contemplated aliphaticcarboxylic acids is preferably effected at temperatures ranging from C.to 100 C. If desired, however, the reaction can be carried out attemperatures ranging from 0 C. to 150 C. or 225 C. As noted, thereaction also can be conducted in the presence or absence of organicsolvents such as benzene, toluene, Xylene, cyclohexane, or the like. Theconcentration of the solution employed is determined solely by thelimits of the solubility of the reactants. For practical purposes,solutions of as high concentration as possible are resorted to.

The polymeric titanic acid esters of this invention, particularly thosemade from longer chain acids (8 to 20 carbons) which are organo-solubleoils or low melting waxes, are uniquely highly 6 products of thisinvention useful as anti-sludging agents for lubricating oilsparticularly for internal combustion engines. This use is illustratedbelow:

Pastes (10 g.), prepared by grinding 30 g. of a carbon black with 400 g.of a white mineral oil, were placed in 4-ounce petroleum samplebottleswhich were filled to the shoulder with kerosene having dissolved therein0.2 g. of polytitanyl ester-carboxylates with TiOz contents of 15.6% and21.15%, respectively. The titanium compounds materially reduced the rateof settling of the carbon, the ester-carboxylate of lower TiOz contentbeing the more effective.

The polymeric titanium ester carboxylates are also useful inwater-repellent compositions, as illustrated below:

A polymeric isopropoxytitanium stearate (0.3 part) (Ti content, 9.33%)and paraifin wax (5.7 parts) were dissolved in 200 parts of Stoddardsolvent. Undyed cotton sateen fabric was padded with this solution andpassed through squeeze rolls under pressure so that the weight in thewet state Was about twice the dry weight. The treated fabric was airdried and then heated ten minutes at 120 C. It had a soft hand, a lightcream color, and good water-repellent properties.

In addition to the uses illustrated, the polymeric titanium esterproducts of this invention are also useful as pigment (both organic orinorganic white or colored types) dispersing agents, lead scavengers ingasoline, dry cleaning soaps, rust inhibitors for steel, pour pointdepressants for lubricating oils, crosslinking agents for polymers,components of greases, catalysts for ester interchange reactions,components of cosmetic preparations, etc.

My novel products, particularly those of higher molecular weight, arealso useful as plasticizers and modifiers for resinous materials. Theyare especially useful for increasing the hardness and. reducing thedrying time of coating compositions, such as paints, enamels, lacquers,and particularly of alkyd resins.

soluble in petroleum and other hydrocarbon solvents. As has beenindicated, the resulting hydrocarbon solutions exhibit novel,surface-active properties, illustrations of which are given below:

Solutions were prepared of one gram of polytitanyl ester-carboxylateswith TiOz contents of 15.60% and 21.15%, respectively, in 100 cc. ofkerosene. Flowable dispersions resulted when 10 cc. portions of thesolutions were stirred with 1 0 g. of carbon black. In the absence ofthe esterearboxylates, mixtures of 10 g. of carbon black and 10 cc. ofkerosene were stiff and non-flow able. Dispersions of the above type canbe emp oyed as jet engine and other fuels.

Such surface-active properties also render the I claim as my invention:

1. A method for producing an organo-soluble polymeric titanium compoundwhich comprises reacting an organic ester of orthotitanic acid havingthe formula Ti(OR)4, in which R is a hydrocarbon radical selected fromthe group consisting of alkyl, cycloalkyl, aryl, and aralkyl, with ananhydrous aliphatic carboxylic acid, employing in the reaction at leastmol of acid per mol of ester, and continuing said reaction until asoluble polymeric ester is obtained.

2. A method for producnig an organo-soluble polymeric titanium compoundwhich comprises reacting an organic ester of orthotitanic acid havingthe formula THORM, in which R is a hydrocarbon radical selected from thegroup consisting of alkyl, cycloalkyl, aryl, and aralkyl, with ananhydrous aliphatic carboxylic acid, employing in the reaction at least2 mols of acid per mol of ester, and continuing said reaction until asoluble polymeric ester is obtained.

3. A method for preparing a stable, soluble polymeric titanic acid esterwhich comprises reacting a tetrasubstituted alkyl ester of orthotitanicacid with an anhydrous, saturated aliphatic carboxylic acid, employingin the reaction from to 4 mols of carboxylic acid per mol of said alkylester, and continuing said reaction until a soluble polymeric ester isformed.

4. A method for preparing a stable, soluble,

polymeric titanic acid ester which comprises .heating a tetrasubstitutedalkyl ester of orthotitanic acid in the presence of an anhydrous,

saturated, aliphatic carboxlic acid, the amount .of the latter acidbeing in the ratio of from to 2 mols per mol of the ester, andcontinuing said heating until a soluble polymeric ester is formed.

-at least 2 mols of carboxylic acid per mol of orthotitanate, continuingsaid reaction until a soluble polymeric ester is formed, and recoveringsaid polymeric product from the reaction products.

6.,A method for preparing a stable, organesoluble, polymeric titanicacid ester which comprises heating a reaction mixture of a tetrasub-.stituted alkyl ortho-titanate and an anhydrous, aliphatic, saturatedmonocarboxylic acid, em-

ploying in said mixture at least mol of acid per mol of titanate,continuing said heating until a soluble polymeric ester is formed, andrecovering the ester product from the resulting reaction product.

.7. A method for preparing a stable, soluble, polymeric titanic acidester which comprises heating a tetrasubstituted alkyl ortho-titanate inthe presence of glacial acetic acid, the molecular ratio of the titanateto the acid ranging from to 2 mols of acid per mol of titanate, andcontinuing said heating until a soluble polymeric ester is formed.

8. A method for preparing a stable, polymeric titanic acid ester whichcomprises heating, at temperatures ranging from 50 C. to 100 C.,tetraethyl titanate with an amount of glacial acetic acid ranging from/2 to 2 mols per mol of said titanate and continuing said heating untila soluble polymeric ester is formed.

9. As a new organo-soluble polymeric titanium compound, the productobtained by reacting an organic ester of ortho-titanic acid,corresponding to the formula Ti(OR)4 in which R is a hydrocarbon radicalselected from the group consisting of alkyl, cycloalkyl, aryl, andaralkyl, with at least a half molar equivalent of an anhydrous aliphaticcarboxylic acid per mol of said ester.

10. As a new organo-soluble polymeric titanium ester, the reactionproduct of a tetrasubstituted alkyl ortho-titanate with a least onemolar equivalent of an anhydrous, saturated, aliphatic monocarboxylicacid per mol of said titanate.

11. As a new organo-soluble polymeric titanium ester, the reactionproduct of a tetrasubstituted alkyl ortho-titanate with from 1 to 4molar equivalents of an anhydrous, saturated, aliphatic monocarboxylicacid per mol of said orthotitanate.

12. As a new organo-soluble polymeric titanium ester,.the reactionproduct of a tetrasubstituted alkyl ortho-titanate with at least 2 molarequivalents of an anhydrous, saturated, aliphatic monocarboxylic acidcontaining from 8-20 carbon atoms.

13. A method for preparing a stable, soluble, polymeric, titanic acidester which comprises heating tetrabutyl orthotitanate in the presenceof glacial acetic acid, the molecular ratio of the titanate to the acidranging from to 2 mols'of acid per mol of titanate, and continuing saidheating until a soluble polymeric ester is formed.

14. A method for preparing a stable, soluble, polymeric, titanic acidester which comprises heating tetraethyl orthotitanate in the presenceof an anhydrous, saturated, aliphatic, carboxylic acid, the amount ofthe latter being in the ratio of from to 2 mols per mol of the ester,and continuing said heating until a soluble polymeric ester is formed.

15. A method for preparing a stable, soluble, polymeric titanic acidester which comprises heating tetrabutyl orthotitanate in the presenceof an anhydrous, saturated, aliphatic, carboxylic acid, the amount ofthe latter being in the ratio of from /2 to 2 mols per mol of the esterand continuing said heating until a soluble polymeric ester is formed.

16. A method for producing a hydrocarbonsoluble polymeric titanium esterwhich comprises reacting tetraisopropyl titanate in the presence of anorganic solvent with stearic acid, employing in the reaction from 2 to 4mols of acid per mol of titanate, continuing said reaction until thesoluble polymeric ester is formed, and recovering said polymeric productfrom the products of reaction.

17. A method for producing a hydrocarbonsoluble polymeric titanium esterwhich comprises reacting tetrabutyl titanate in the presence of anorganic solvent with stearic acid, employing in the reaction from 2 to 4mols of acid per mol of titanate, continuing said reaction until thesoluble polymeric ester is formed, and recovering said polymeric productfrom the products of reaction.

18. As a new organo-soluble polymeric titanium ester, the reactionproduct of an organic ester of orthotitanic acid having the formulaTi(OR)4, wherein R is a hydrocarbon radical selected from the groupconsisting of alkyl, cycloalkyL'aryl, and aralkyl, with at least 2 molsOf an anhydrous, aliphatic monocarboxylic acid containing from 8-20carbon atoms.

19. As a new hydrocarbon-soluble polymeric titanium ester, the reactionproduct of tetraisopropyl titanate with from 2-4 molar equivalents ofstearic acid.

20. As a new hydrocarbon-soluble polymeric titanium ester, the reactionproduct of tetrabutyl titanate with from 2-4 molar equivalents ofstearic acid.

CARL MARTIN 'LANGKAMMERER.

REFERENCES CITED .The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,467,177 Zimmer Apr. 12, 1949FOREIGN PATENTS Number Country Date 125,450 Australia Sept. 25, 1947OTHER REFERENCES Scientific Section Educational Bureau American Paintand Varnish Manufacturers Association Circular No. 366, July 1930.

Paint, Oil and Chemical Review, June 8, 1950, page 40.

9. AS A NEW ORGANO-SOLUBLE POLYMERIC TITANIUM COMPOUND, THE PRODUCTOBTAINED BY REACTING AN ORGANIC ESTER OF ORTHO-TITANIC ACID,CORRESPONDING TO THE FORMULA TI(OR)4 IN WHICH R IS A HYDROCARBON RADICALSELECTED FORM THE GROUP CONSISTING OF ALKYL, CYCLOALKYL, ARYL, ANDARALKYL, WITH AT LEAST A HALF MOLAR EQUIVALENT OF AN ANHYDROUS ALIPHATICCARBOXYLIC ACID PER MOL OF SAID ESTER.